Containment procedures specify container size, but not an implied fact that this thing doesn't replicate plastic. Don't worry about specifying how its box is, if what the box is made of is what's important.

The fact that the anomaly specifically replicated complex mechanisms and organisms should be mentioned instead of "any object". Maybe explain after that it will assume the form of objects like a table of a book if nothing else is nearby.

The sub-designation (XXXX-1) is a bit confusing. It generates a replica of an object with mass from nowhere, I think… but how are these instances terminated, if they posses the chemical composition of the original slime?

Not sure why this thing is corrosive in the first place. What I'm getting is that it's trying to replicate objects to blend in, but it's not predatory.

Overall, this isn't too interesting. It's dangerous components don't stray too far from other biohazardous anomalies, and it's slime-like properties and generation of mass just exist alongside it without reason.

I think you're focusing too much on the aforementioned properties of the anomaly, without realizing that's not what makes the article interesting. Answering more "why?" questions about the anomaly can lead to a greater reader investment. Why is a corrosive cave slime living underground? Is it really just a conglomerate of bacteria? Does it simply create mimics to reproduce? Why doesn't it reproduce without any objects?

Also, you should rename your sandbox's URL to your username in "Options" at the bottom of the page. The URL shouldn't be the article's title.